Question

In 2011, the mean property crime rate (per 100,000 people) for the 10 states in the Northeast was 2400; the standard deviation was 400. Assume the distribution of property crime rates is approximately unimodal and symmetric.
a. Approximately what percentage of northeastern states would you expect to have property crime rates between 1600 and 3200?
b. Approximately what percentage of northeastern states would you expect to have property crime rates between 2000 and 2800?
c. If someone guessed that the property crime rate in one northeastern state was 400, would you agree that number was consistent with this data set?